Electrostatic voltmeter (ESV) zero offset adjustment
US5119131A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 5, 1991 |
| Grant date | Jun 2, 1992 |
| Priority date | — |
| Expiry date | Sep 5, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/5041
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a single pass, tri-level imaging apparatus, erroneous voltage readings of an Electrostatic Voltmeter (ESV) which has become contaminated by charged particles (i.e. toner) are negated by using two ESVs. During each cycle up following a normal cycle down, a pair of Electrostatic Voltmeters (ESVs) are utilized to measure the voltage level on a portion of relatively uncharged portion of a photoreceptor (P/R). Using one of the ESVs, which is less prone to contamination, as a reference, the zero offset of the other is adjusted to achieve the same residual P/R voltage reading. The difference in the readings which is due to toner contamination is the zero offset between the two ESVs. The offset is used to adjust all subsequent voltage readings of the ESV until a new offset is measured.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.